These engines are notorious for sucking oil through the intake gasket. I have personally fought this issue on an engine. They can consume a substantial amount of oil that way and since that oil contains no octane, it can make the engine much more prone to spark knock.
Very possible.
Another diagnostic trick is to temporarily replace your regular engine oil with 100% synthetic, ash-less, 2 stroke 30 wt oil to do a test drive,
This unique synthetic oil has a special formulation to reduce detonation.
